percpu: clean up percpu constants

Impact: cleaup

Make the following cleanups.

* There isn't much arch-specific about PERCPU_MODULE_RESERVE.  Always
  define it whether arch overrides PERCPU_ENOUGH_ROOM or not.

* blackfin overrides PERCPU_ENOUGH_ROOM to align static area size.  Do
  it by default.

* percpu allocation sizes doesn't have much to do with the page size.
  Don't use PAGE_SHIFT in their definition.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Bryan Wu <cooloney@kernel.org>

2 files changed, 13 insertions, 21 deletions

diff --git a/arch/blackfin/include/asm/percpu.h b/arch/blackfin/include/asm/percpu.h
index 797c0c165069..c94c7bc88c71 100644
--- a/arch/blackfin/include/asm/percpu.h
+++ b/arch/blackfin/include/asm/percpu.h
@@ -3,14 +3,4 @@
 
 #include <asm-generic/percpu.h>
 
-#ifdef CONFIG_MODULES
-#define PERCPU_MODULE_RESERVE 8192
-#else
-#define PERCPU_MODULE_RESERVE 0
-#endif
-
-#define PERCPU_ENOUGH_ROOM \
-        (ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES) + \
-         PERCPU_MODULE_RESERVE)
-
 #endif  /* __ARCH_BLACKFIN_PERCPU__ */
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index 545b068bcb70..2d34b038fe70 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -5,6 +5,7 @@
 #include <linux/slab.h> /* For kmalloc() */
 #include <linux/smp.h>
 #include <linux/cpumask.h>
+#include <linux/pfn.h>
 
 #include <asm/percpu.h>
 
@@ -52,17 +53,18 @@
 #define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var)
 #define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var)
 
-/* Enough to cover all DEFINE_PER_CPUs in kernel, including modules. */
-#ifndef PERCPU_ENOUGH_ROOM
+/* enough to cover all DEFINE_PER_CPUs in modules */
 #ifdef CONFIG_MODULES
-#define PERCPU_MODULE_RESERVE   8192
+#define PERCPU_MODULE_RESERVE           (8 << 10)
 #else
-#define PERCPU_MODULE_RESERVE   0
+#define PERCPU_MODULE_RESERVE           0
 #endif
 
+#ifndef PERCPU_ENOUGH_ROOM
 #define PERCPU_ENOUGH_ROOM                                              \
-        (__per_cpu_end - __per_cpu_start + PERCPU_MODULE_RESERVE)
-#endif  /* PERCPU_ENOUGH_ROOM */
+        (ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES) +      \
+         PERCPU_MODULE_RESERVE)
+#endif
 
 /*
  * Must be an lvalue. Since @var must be a simple identifier,
@@ -79,7 +81,7 @@
 #ifdef CONFIG_HAVE_DYNAMIC_PER_CPU_AREA
 
 /* minimum unit size, also is the maximum supported allocation size */
-#define PCPU_MIN_UNIT_SIZE              (16UL << PAGE_SHIFT)
+#define PCPU_MIN_UNIT_SIZE              PFN_ALIGN(64 << 10)
 
 /*
  * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy
@@ -96,15 +98,15 @@
 #ifndef PERCPU_DYNAMIC_RESERVE
 #  if BITS_PER_LONG > 32
 #    ifdef CONFIG_MODULES
-#      define PERCPU_DYNAMIC_RESERVE    (6 << PAGE_SHIFT)
+#      define PERCPU_DYNAMIC_RESERVE    (24 << 10)
 #    else
-#      define PERCPU_DYNAMIC_RESERVE    (4 << PAGE_SHIFT)
+#      define PERCPU_DYNAMIC_RESERVE    (16 << 10)
 #    endif
 #  else
 #    ifdef CONFIG_MODULES
-#      define PERCPU_DYNAMIC_RESERVE    (4 << PAGE_SHIFT)
+#      define PERCPU_DYNAMIC_RESERVE    (16 << 10)
 #    else
-#      define PERCPU_DYNAMIC_RESERVE    (2 << PAGE_SHIFT)
+#      define PERCPU_DYNAMIC_RESERVE    (8 << 10)
 #    endif
 #  endif
 #endif  /* PERCPU_DYNAMIC_RESERVE */